The invention relates to a method and a circuit arrangement configured for driving a field-effect-controlled transistor whose switching behavior is intended to be specifically influenced.
The transient switching behavior of a field-effect-controlled transistor (for example MOSFET, IGBT etc.) is influenced by the temporally dependent amount of charge in the gate of the transistor. The temporal profile of this amount of charge is determined by the temporally dependent injection of the gate current. The transient profiles of the load current and the voltage across the load path and thus also the turn-on and turn-off losses can be influenced by prescribing a particular gate current when turning the transistor on and off.
In the case of known driver circuits for driving the gate, the current which charges the gate-source capacitance of the transistor to be controlled is usually determined in a very simple manner by a gate resistor which connects the driver circuit and the gate connection of the transistor. The gate current is thus dependent on the voltage difference between the gate voltage and the control voltage provided by the driver circuit and on the gate resistance. However, more complex influencing which could determine the exact switching behavior of the transistor is thus not possible, and there is a general need for a method for driving a field-effect-controlled transistor in order to influence the switching operation in a flexible manner.
For these and other reasons, there is a need for the present invention.